Gliomas are a significant cause of morbidity and mortality, and thus have been the focus of frequent basic biologic, basic genetic, and clinical investigations. Numerous genetic and biologic alterations associated with gliomas have been described. However, many of the specific genes involved in gliomas have yet to be identified. A great deal still needs to be learned about the mechanisms by which the known genes are involved in the pathogenesis of gliomas. Furthermore, while much has been learned about the biology and genetics of gliomas, little of this information has been translated into clinical practice. There are still problems with the morphologic classification of gliomas - especially oligodendrogliomas and mixed oligoastrocytomas. It is difficult to predict which patients with anaplastic astrocytomas will suffer early recurrence. And while some gliomas with specific genetic alterations seem to respond to chemotherapy (e.g., Cairncross et al., JNCI 90:1473,1998), these observations need to be confirmed and extended and additional therapeutic genetic targets identified and/or developed. Through four projects and two cores this program, which builds on the past experience of the Glioma Marker Network (GMN) consortium, will study the basic biology of several specific biochemical and genetic alterations associated with gliomas. It will also continue to evaluate the predictive, prognostic, and pathologic relevance of these alterations. Project 1 will study the biologic and clinical relevance of 7q gain in gliomas, with emphasis on the mechanism by which this alteration predicts a poorer prognosis. Project 2 will evaluate the function of mutated and amplified EGFR in gliomas and will test several potential therapeutic approaches targeting these mutant receptors. Project 3 will identify and study the function of the 19q gene associated with gliomas and associated with a prolonged response of some gliomas to chemotherapy. Project 4 will study the biologic and clinical relevance of glycolipid and glycosyltransferase alterations in gliomas. Thus, through these projects, this highly-interactive and experienced program will make significant progress toward understanding the pathogenesis of gliomas, and translating this knowledge into new diagnostic and therapeutic tools.